Manufacturing Carbon-Doped Stamp With Surface Microstructures for Rapid and Reliable Micro-LED Transfer Process

The laser-assisted micro-transfer printing (Laser-assisted <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>TP) technology is considered a highly promising solution for the mass transfer of micro-LEDs, which offers a series of benefits, including high transfer accuracy, fast transfer speed, and selective transfer capability, but it also presents a risk of micro-LED damage due to laser exposure. To solve this issue, this article proposes an improvement to the Laser-assisted <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>TP by introducing a novel carbon particle-doped polydimethylsiloxane (PDMS) stamp (CPD stamp). The carbon particles doped in the stamp enhance the laser absorption capability of the stamp, thereby reducing chip damage. At the same time, the pristine adhesion strength of CPD stamp declines by 98.35% attributed to the design of surface microstructure, accelerating chip ejection and improving the transfer speed. After optimization, the optimal CPD stamp demonstrates the potential for high-speed transfer, as it is demonstrated that the detachment of the chips from the optimal CPD stamp occurs within 117 ms. Meanwhile, the micro-LEDs are successfully transferred by optimal CPD stamp without degradation. In conclusion, the CPD stamp proposed in this article provides an effective solution to the drawbacks of Laser-assisted <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>TP, potentially advancing the commercialization process of this technology